<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2017/9/20
 * Time: 14:43
 */

$email = "ahju@nchen@QQ.COM";
var_dump(strrpos($email,"@"));

$fileName='E:\Files\PHP\index.php';
$s = strrchr($fileName,'\\');
var_dump($s);